Improved Light Absorption of GaInP/GaAs/Ge Solar Cell Modules With Micro/Nanoengineered Coverglasses

Abstract

We report on advanced types of coverglasses, which include the hierarchical micro-and subwavelength-structured surfaces for improved absorption efficiency of photovoltaic modules. Prism-shaped microstructures (PSMSs) help eliminate the optical shading caused by the metal grid of solar cells. The subwavelength structures (SWSs) with a tapered shape behave as a refractive index matching layer to reduce the surface reflection at the interface of air and coverglass. The geometries of the PSMSs and SWSs were designed by ray-tracing and the rigorous coupled-wave analysis method simulations, respectively, which provided the design guidelines. The PSMSs and SWSs were fabricated by a simple two-step process consisting of an isotropic wet etching process with hydrofluoric acid solution using a SiN x mask and a self-masked dry etching process, respectively. A hybrid patterned coverglass incorporating the PSMSs with SWSs were mounted on GaInP/(In)GaAs/Ge triple-junction solar cells with a precise alignment process. The measured power conversion efficiency of the subreceiver module with the patterned glass reached 32.97% for 1 sun, which is 11.19% higher compared with a subreceiver module with a flat coverglass.

Enhanced Light Harvesting in Photovoltaic Devices Using an Edge-Located One-Dimensional Grating Polydimethylsiloxane Membrane

“…Typically, encapsulants play a key role in solar modules to serve as a protective barrier. − Moreover, for enhancing solar harvesting, encapsulation materials can be sophisticatedly structured to manage light transmission and deliver light into the active area of solar cells. So far, structural approaches, such as the use of prisms, beer steering coatings, blazed phase gratings, TiO 2 xerogel diffraction gratings, and nanocone arrays, have been reported to improve conversion efficiencies with encapsulants. − Contrary to fundamental changes in solar cell structures, since encapsulation is the final step in the modularization of solar cells, simple structure and fabrication are required to be close to commercialization. Typically, the diffraction grating structure is one of the candidates meeting this demand, but for practical applications, it is necessary to optimize the grating parameters with diffraction orders and to consider the angular change of the incident light. ,− Furthermore, for the commercial installation of solar modules, large-scale array formation is inevitable.…”

Using Spin-Coated Silver Nanoparticles/Zinc Oxide Thin Films to Improve the Efficiency of GaInP/(In)GaAs/Ge Solar Cells

“…The ZnO nanowire ARC combined with AZO can reduce reflectance in the short-wavelength range and achieve high conversion efficiency. Kang et al [ 16 ] utilized coverglasses with hierarchical microstructured and subwavelength-structured surfaces to improve the absorption efficiency of InGaP/GaAs/Ge TJ solar cell modules. The short current density (J sc ) and conversion efficiency of patterned coverglass-solar-cell modules were enhanced by 12.14% and 11.19%, respectively, compared with those of a conventional solar cell module.…”